CONSTANTS FIF_PROMISC_IN_BSS promiscuous mode within
your BSS, think of the BSS as your network segment and then
this corresponds to the regular ethernet device promiscuous
mode.

FIF_ALLMULTI pass all multicast frames, this is used if
requested by the user or if the hardware is not capable of
filtering by multicast address.

FIF_FCSFAIL pass frames with failed FCS (but you need to
set the RX_FLAG_FAILED_FCS_CRC for them)

FIF_PLCPFAIL pass frames with failed PLCP CRC (but you
need to set the RX_FLAG_FAILED_PLCP_CRC for them

FIF_BCN_PRBRESP_PROMISC This flag is set during scanning
to indicate to the hardware that it should not filter
beacons or probe responses by BSSID. Filtering them can
greatly reduce the amount of processing mac80211 needs to do
and the amount of CPU wakeups, so you should honour this
flag if possible.

FIF_CONTROL pass control frames (except for PS Poll), if
PROMISC_IN_BSS is not set then only those addressed to this
station.

FIF_OTHER_BSS pass frames destined to other BSSes

FIF_PSPOLL pass PS Poll frames, if PROMISC_IN_BSS is not
set then only those addressed to this station.

FIF_PROBE_REQ pass probe request frames

HW QUEUE CONTROL These flags determine what the filter
in hardware should be programmed to let through and what
should not be passed to the stack. It is always safe to pass
more frames than requested, but this has negative impact on
power consumption.